a Wages do not include compensation (supplements to
wages and salaries such as pension, profit-sharing, and other retirement plans,
and health, life, and unemployment insurance).

b Defined as services incidental to transportation,
such as forwarding and packing services and arranging passenger travel and freight
transportation.

SOURCE: 1960-2000: U.S. Department of Commerce, Bureau
of Economic Analysis, National Income and Products Accounts, tables 6.3b and 6.3c,
Internet site http://www.bea.doc.gov/bea/dn1.htm
as of Aug. 3, 2001.